Third Project Assignment (due Friday, April 20, 4:00 p.m.)

(Preliminary data summary due Thursday, April 12.)

As announced in class, this project will be a "household energy audit".
Pretend that you have been hired to assess the total energy use of
one household, and to suggest ways in which this household could
use less energy and save money.

The household that you audit can be your own, or that of a friend
or family member. Ideally, you should have access to a complete
set of utility bills (gas and electric) for the household for one year.
You should also be able to go into the home to see how energy is
being used at various times, and you should have a way of estimating
how much gasoline is used for driving to various destinations.
If your data is incomplete you can still do the project, but it will
be easier if you can obtain fairly complete data.

After choosing a household, your first task is to determine the
total annual use of electricity, natural gas, and gasoline. Gather
the utility bills and records of gasoline purchase, or estimate the
amounts in the best way you can. (For instance, you can estimate the
amount of gasoline used from the number of miles driven and the
miles per gallon of each vehicle. Past odometer readings may be
written on registration or maintenance receipts, and you can measure
the miles per gallon between the next two fill-ups by noting the
odometer readings and number of gallons purchased.) Please turn in
a one-page summary of total energy useage, in each of the three
forms, on Thursday, April 12. Include a brief explanation of how
you obtained each total. Show the amounts of energy both in
billing units (decatherms, kilowatt-hours, and gallons) and in
one common unit that you find convenient (you can choose any of these
three or perhaps kilocalories or jelly donuts). Also show the amount
of money spent, per year, on each form of energy.

Next, analyze the major ways in which each type of energy is used.
For natural gas, the uses will probably be space heating, water heating,
and perhaps cooking and clothes drying. For gasoline, try to divide trips
according to purpose: commuting to work or school, shopping, recreation, etc.
Significant uses of electricity may include air conditioner, swamp cooler,
refrigerator, freezer, lights (indoor and outdoor), heating, cooking, laundry,
television, computer, and perhaps others. (Don't worry about appliances
that use very little power, such as clocks, or appliances that are
used only rarely, such as power tools.)

Ideally, you should be able to calculate the annual energy consumption
for each of these specific uses. In some cases, the calculation will
probably be fairly easy, while in other cases, considerable ingenuity
may be required. Seasonal variations in utility bills will provide
useful clues. Power ratings of some appliances (like light bulbs)
are written right on them, although in some cases (such as stereo
equipment) the average useage is always much less than the number written.
For newer appliances you may still have the yellow energy rating
sticker. You may be able to determine the energy use of your
refrigerator by reading your electric meter before and after a
period of several hours when no other major appliances are used.
Once you know this, you can estimate the use of an electric stove
or dryer with further meter readings. Of course, the sum of all the
specific uses of each major type of energy should add up to the
total that you previously determined.

The main result of this project, then, will be an itemized list
showing the amount of energy used for each purpose in one year (both
in common units and in your standard unit),
along with the amount of money spent for each use. In the text
of your writeup, include a brief description of how you determined each
numerical value. Also please include an introductory section
describing the type of home (size, age, house or
apartment), the number of adults and children living there, and
any other basic information that may be important for context.

In the final section of your report, give some specific suggestions
on how this household could save energy and money. Be as quantitative
as you can--that is, for each of your suggestions, estimate the
amount of energy and money that would be saved in one year. Again,
some of these estimates will be fairly straightforward, while
others might require considerable ingenuity. Concentrate on changes
that could be made without too much inconvenience or extra expense.
Here are a few of the measures that you might consider: changing the
thermostat settings in various ways; closing off unused rooms; caulking
and weatherstripping; improving windows in various ways; adding insulation;
hanging laundry to dry;
replacing lights, appliances, and/or cars with more efficient models;
replacing a central air conditioner with a swamp cooler; controlling
outdoor lights with a motion detector; eliminating pure waste such
as an empty freezer or lights left on while away; taking the bus to
work or school; walking, bicycling, or carpooling. For each measure
that you recommend, include a brief explanation of how you
estimated the amount it would save. Finally, add up the
total savings (in energy units and in dollars) from all recommended conservation
measures.

The exact format of your report is somewhat flexible, as long as
it includes all the information described above. Your report should
be readable to a typical adult who has not studied any science.
Although a formal "abstract" would be out of place in such a report,
you may wish to start with an informal summary, since most readers
want to see the "bottom line" as soon as possible.

Please keep me informed of your progress on this assignment, and
ask as many questions as you like. For some of the trickier estimates
and calculations, I may be able to point you to some useful data.